Expand Full Text Search Capabilities

Our FTS capabilities are pretty limited right now -- REGEXP_MATCH does a primitive regex match and TEXT_MATCHES is simply a wrapper around basic Lucene level searching (does not expose fuzzy queries or the option to rank).

This issue states a proposal for expanding our FTS capabilities with the following initial ideas:

1. Support LIKE operator (https://www.w3schools.com/sql/sql_like.asp).
2. Improve TEXT_MATCH (see #7215 , #7216 and #7217 ).
3. Allow ranked searches (something on the lines of https://www.postgresql.org/docs/9.5/textsearch-controls.html#TEXTSEARCH-RANKING)

No source file, test, or entry point is named. Begin by reviewing the existing REGEXP_MATCH and TEXT_MATCHES implementations, then read issues #7215, #7216, and #7217 before deciding how LIKE support, improved TEXT_MATCH behavior, fuzzy queries, and ranked searches should be specified and tested.

Written by the indexing model from the issue text.